Governing device for pneumatic piano-player action.



M. CLARK.

GOVERNING DEVICE FOR PNEUMATIC PIANO PLAYER ACTION.

APPLICATION FILED MOM. 1915. D 1,183,1 68. PAIANIAII May 16I191b 2 sIIEEIs-sIIEEf I.

IVI. CLARK. v

GOVERNING DEVICE FOR PNEUMATIC PIANO PLAYER ACTION.

APPLICATION FILED AUG-20, I9I5- Patented May 16, 1916.

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MELVILLE CLARK, OF CHICAGO, ILLINOIS, ASSIGNOR TO IIIELVILLE CLARK El'ANO COMPANY, OF CHICAGO, ILLINOIS, A

COREORATION OF ILLIN 01S.

GOVERNING DEVICE FOR PNEUMATIC PIANO-ELAYER ACTION.

/ Application filed August 20, 1915.

To (/17 r/iaom it may concern:

Be it known that l, MnLviLLn CLARK, a citizen of the l nited States, residing; at Chicago, in the county of Cook and State of lllinois. have invented new and useful ln'iprovements in Governing Dev-ices for lneumatic Piano-Player Action, of which the following is a specification, reference being had to the accompanying drawings, forming: a part thereof.

The purpose of this invention is to provide an improved construction on autopneumatic piano players for controlling the expression, or loudness and softness of the ylayin I lt consists in the elements and features of construction shown and described.

In the drawings: l i ejure 1 is a foreandaft vertical section, partly diagrammatic, throughthe portion of a piano containing the player mechanism en'ibodying this invention. Fig. l

2 is a forward side elevation .of the duct board of the exhaust mecl'ianisn'i, and the parts mounted thereon constituting Fig. is a section at the Fig. 4- is a section at the line, ll, on Fig. 5. Fig. 5 is a section at the line, 5-5, on Fig. 2. Fig. 6 is a section at the line, G6, on Fig' 5.

The present invention is concerned only with the parts involved in the air control, and other parts of the instrument are shown only to indicate the relative position in the instrument of these parts which are concerned.

The drawings show in conventional form and the usual position, the key-bottom, A, of the piano, manual keys, ll, action comprising the primary pneumatics or partial vacuum chamber, C, with the usual connection by ducts, l), to the tracker,

E. and containing the primary pneumatics,

this invention. line, 33, on Fig.

(l, (shown-by dotted line in the drawing) controlled in the usual manner the striker or motor pneun'iatics, (l, acting upon the manual keys, B. llelow the key bottom, Ev, there is mounted the exhaust duct board, ll, upon which are pumpers, Ll, one only being shown, and the reserve bellows or receiver, K, held normally distended by the customary spring, K, collapsed by action of the IHUHDQI'S and acting by expansion to exhaust the air from the chamber, U. through duct, H, in the board, ill, and

Specification of Letters Patent.

pneun'iaticresisted by the latentetl May 16, 1916.

Serial No. 46,422.

through a governor bellows, L, and pipe, IF. connected therewith and with the chamber. C. all operating in the usual manner of such devices. Mounted in any convenient position. as for example, on the. lower portion of the exhaust duct board, H, is the governor bellows. l connected by duct, h, with ducts ll and thereby with the receiver. K. and having its moving wall provided with the valve, L, which closes the port, it, of the duct, h, cutting olf communication from the governor bellows. L, to the receiver, K, when said governor bellows is collapsed so as to seat that valve, whose seating is therefore determined by the resistance offered to the collapse of the governor bellows, L. The governor bellows, L, communicating by the port, [1, and tube, 1 with the primary pneumatic chamber, (7, and being thus interposed between the receiver, K, and said primary pneumatic chamber, t, operates to control the exhaust tension in said primary pneumatic chamber. All of the parts thus far described are constructed and operated in a familiar manner and according to familiar principles and may be mounted in any convenient relation to each other in the piano case.

Inasmuch as the loudness or softness of the playing depends upon the exhaust tension operative in the primary pneumatic chamber, C, and since this exhaust tension depends upon the resistance of the governor bellows, L, to collapse, (seating its valve, L), it will be seen that the loudness and. softness of playing may be controlled by any means which controls the resistance of this governor pneun'iatic. L, to collapsing. For modifying this resistance as desired, either automatically or by hand control, (according to the sin'iplementary devices provided), there is provided a supplemental governor bellows, M, mounted conveniently, though not necessarily, upon the duct board, H, having its moving wall connected with the moving wall of the governor bellows, L, by means of a spring, 5?, nected to the two moving: walls that the collapse of either of said bellows tends through the spring connection to expand the other; that is, so that the collapse of either bellows tension of the spring, which tension is increased by such collapse which is so con-- of either bellows. By reason of this spring connection between the two moving walls of the two governor bellows, it will be seen that the collapse of the supplemental govcrnor bellows, M, to a less or greater extent increasing the tension of the spring, N, operating to hold the governor-bellows, L, expanded, will increase the exhaust tension ope 'ative under the control of said governor bellows, L, in the primary pneumatic chamber, that is, up to the maximum exhaust tension which may be produced in the receiver. K, by the pumpers. The connection of the spring, N, to one governor bellows or the other is made adjustable to vary the minimum or basic tension of the spring, that is, the tension operating when the two bellows are both expanded to themaxinnun. As illustrated, and most conveniently, this adjustment is eii'ected by making the spring, as shown, a flat steel bar bent to form a heel, N lodged upon the moving wall of the bellows. M. where it may be secured by a screw, /1, holding it loosely, the spring being further secured to said moving wall by a screw, N, which may be screwed in more or less-to any the initial tension of the spring. The supplemental governor bellows, M, is connected with the receiver or retaining bellows, K, so as to be exposed to the exhaust tension derivable from said receiver bellows, by means of ducts which are controlled by a 'alve mechanism operated to .ail'ord more or less restricted connnunication from 'said receiver bellows and said governor bellows, M, and said governor bellows, M, has a leal-z-port, m, for the admission. of atmospheric air; so that, so long as the communication from the receiver K to said governor bellows, M, is restricted to less than the capacity of the lealcport, said governor bellows, M, is not collapsed at all, and the degree of its collapse depends upon the excess of the exhaust communication atforded between said governor bellows, MI, and the receiver, K, over the capacity of said leak-port, the parts being designed to be so proportioned and related to the strength of the spring, N, and that when the communiration between the receiving bellows. K, and said governor bellows, M, is open to the widest extent, and the exhaust tension produced in the receiver, K, by the pumpers is the maximum which the pumpers can produce, the governor bellows, M, will be completely collapsed against the resistance of the spring, N, and will thereby tension that spring to the maximum degree necessary for holding the governor bellows, L, expanded so as to hold the valve, L, off its seat against the full tension of the receiver, K, tending to collapse said governor, L, thereby admitting said t'ull ex haust tension past said valve. [11. to the primary pneumatic chamber, U, and cansing the loudest playing. The air connections and the valve mechanism which controls the restriction of the communication of exhaust tension from the receiver, K, to

said supplemental described.

The duct, H", in the exhaust duct board, H, leads from the receiver, K, by way of a branch duct, 1, from the duct, P, hereinafter mentioned, to a plurality of ports,

governor, M, will now be (as illustrated, two 72; and 15 which open lows, M. (As a matter of convenience, these ducts may be partly formed by tubes, as illustrated.) A slide valve, 0, mounted to slide upon said valve seat has in its under face toward said seat, pockets, 0 and which are dimensioned so that at proper position upon the valve seat the pocket, 0 bridges over or embraces the two adjacent ports, it and h, and similarly the pocket, 0 bridges and embraces at proper position of the valve the adjacent ports, it and k whereby at said proper positions respectively, the valve affords communication from the receiver, K, by way, either of the duct, 1 b or the duct, 7a.", with the supplemental governor, M, and at other positions of said valve closes such communication. The said pockets and said ports are so situated relatively that at one position in the longitudinal movement of the valvehereinafter referred to as the first position all of said ports are closed, and there is no connnunication from the receivlllf bellows, K, to the said supplemental governor bellows. M: and by movement one step from that position the valve comes to a second position at which the pocket, 0, bridges the ports, it and 7a, and opens communication from the receiver bellows to the governor bellows, M, by way of the ducts, it"; by an additional step movement in the same direction from its fully closed position, the valve coming to its third position brings the pocket, in position to bridge andconmeet the ports, it" and if, and the pockets, into position to close the ports, [L4, there by closing the communication from the receiver bellows to the governor bellows, M, by way of the duct, 71v, and establishing communication between the receiver bellows and said gm'ernor bellows by way of the ducts, it"; by one additional step of movement in thesanie direction, the valve coming to a fourth position continues to close the port, it, and also closes the port, it thereby cutting oil both the lines of communication from the receiver bellows to the governor bellows, M. The air-conducting capacity of said ducts, 7L8 and h", being demasses 8 signed to be different, that of the duct, it, being greater than that of the duct, 72 this result or any other relation between the capacity of the two ducts is obtained by means of taper-pointed screws, m and m of the nature of throttle valves which are set into the duct board, H so as to throttle said air passages respectively, as seen in Fig. 3; the screws being adjustable by means of their exposed heads, so to obtain any desired relation between the air-carrying capacity of the two ducts. lVith this construction, it will be seen that the adjustment of the valve, 0, to the first, second or third positions indicated will afford three different degrees of partial vacuum in the primary pneumatic chamber, and consequently three degrees oi intensity or loudness in the playing, the first position yielding the lowest degree of partial vacuum, being that which corresponds to the minimum tension of the spring, N, permitting the governor pneumatic, L, to collapse and seat its valve, l when the partial vacuum produced in said governor bellows, L, is suilicient to collapse it and seat its valve, L against the minimum tension of the spring, N which results from the same being held by the moving wall. of the supplemental governor, M, at the fully expanded position of the latter; the second degree of partial vacuum in the primary pneumatic chamber, causing a certain degree of loudness of playing, results from setting the valve, 0, to second position at which the exhaustion of air from the supplemental governor, M, in excess of the supply thcreto to the leak-port, m is that which can be produced through the restricted communication afi'orded the duct, h de-' termined by the adjustment of the throttle screw, m the third degree of partial vacuum resulting in the third degree of loudness of playing will be obtained when the supplemental governor pneumatic, M, is collapsed to a greater degree by the greater degree of exhaustion which is afforded through the duct, h", governed. by the adjustment of the throttle screw, of.

At the fourthposition of the valve,-(), at which communication through ducts, 71 and h, is entirely out off, the highest degree of partial vacuum is produced and the loudest playing is obtained by the opening of direct communication from the receiving bellows, K, to the primary pneumatic chamber bypassing the governor bellows, L. Such direct communication is afforded by means of a passage comprising a duct, P, leading to and controlled by a valve, Q, and a duct, P leading to the primary pneumatic chamber, C, "from the valve, Q, which is operated by a motor pneumatic, Q controlled in the familiar manner by a primary pneumatic, Q located in a partial vacuum chamber, Q rendered such by connection with the receiver, K, by means of a branch duct, 7), from the duct, l, said chamber, Q being in commimication by means of a flexible tube, Q", with a port, Q which opens throughthe seat of the valve, 0, at a position which causes it to rcgister 'ith an atmosphere port, 0, in said valve when said valve is at said fourth position. The slide valve, Q, provided with a spring, R, which operates to retract it to closed position whenever by the movement of the valve, 0, to carry the atmosphere port, 0, out of registration with the port, Of, the motor pneumatic, Q. is allowed to expand and thereby ceases to hold said valve at its open position.

For operating the valve, 0., to move it to its several positions above described, any convenient manuallv-opcrable means may be provided such as the slide, S, and the lever, HE extending therefrom to a convenient point at the "front of the instrument within reach of the operator. it is designed also to be operated by automatic means controlled by the note-sheet. for which purpose the primary pneumatic device, ll, may be employed. This device is fully described and shown in my Patent No. 1,013,862, dated, January 9, 1912, and need not be further described here except to state that it comprises two motor pneumatics, U and'U each suitably controlled by primary pneumatics, (not visible) in the 'acuum chamber, U", upon which the motor pncumatics are moui'ited. said primary pncumatics beingrespectively connected by tubes, '11? and u, with ducts of the tracker \vhose mouths, shown, are crossed by perforations in the notesheet, not shown, for operating said motor pneumatics, U and U at proper time to cause'them by their respective pawls, U and ll", to actuate the pin-toothed wheel, U, in one direction or the other, causing it by means of the gear, i on its shaft engaging rack teeth on the slide, S, to move said slide, and thereby the valve, 0, in one direction or the other, in steps corresponding to the four positions of said valve thus described.

I claim:

1. In combination with an air chamber from which is derived pneumatic tension for operating the playing devices, a pneumatically operated valve for governing said tension; a spring which resists the movement of said valve; a pneumatic to whose moving wall the spring is connected for movement of the spring to vary its tension, a. second valve controlling the air connection of said pneumatic, and means for operating said second valve to vary the air communication to said pneumatic and thereby vary the extent of movement of its moving wall for tensioning said spring.

2. In combination with a partial vacuum chamber from which is derived the exhaust tension for oueratimr the playing devices, a

pneumaticallv-operated valve for governing said exhaust tension in said chamber; a spring which resists the movement of said valve: a pneumatic to whose moving wall the spring is connected for movement to vary the tension of the spring; a plurality of exhaust connections for said pneumatic of different capacities, and a second valve device which opens said communications selectively for controlling the force of collapse of said pneumatic.

3. In combination with a partial 'acuum chamber from which is derived the exhaust tension for operating the playing devices, a pneumaticallv-o'perated valve for governing said exhaust tension in said chamber; a spring which resists the movement of said valve; a pneumatic to whose moving Wall the spring is connected for movement to vary the tension of the spring; a plurality of exhaust connections for said pneumatic of graduated capacities; a slide valve which controls said connections. the latter having;-

their ports arranged with respect to the movement of the valve so as to be opened in the order of the graduated capacities of said connections; an atmosphere port controlled. by said slide valve on said path positioned to be uncovered after the last uncovered of said exhaust connection ports; a communication from said partial vacuum chamber to the playing devices which by-passes said pneumatically operated valve; a third valve controlling said by-pass passage; a motor pneumatic for operating said third valve, and a primary pneumatic for controlling said motor pneumatics which is operatively connected with said atmosphere port.

In testimony whereof I. have hereunto set my hand at Chicago, Illinois, this 4th day of August, 1915.

MELVILLE CLARK.

Witnesses Rom. N. BURTON, EDNA M. MAcINTosn. 

